When treating wounds, occasionally wounds are encountered that are best described as “tunneling” wounds. A tunneling wound is substantially tunnel-shaped, having an opening at the surface and extending into the flesh, forming a tunnel that is usually longer, and sometimes substantially longer, than the width of the opening. Tunneling wounds can occur by themselves or in combination with a larger open wound, which may include one or more tunneling wounds. Because of their depth, tunneling wounds can present significant risks of infection and can be particularly difficult to heal completely. Thus, it is desirable to provide treatment that removes wound exudates (which can support bacterial growth) and promotes healing of a tunneling wound, including the deepest portions of the wound. Poor healing in the deepest portions of a wound can lead to abscesses if the shallower portion of the wound heals first and closes off the tunnel.
Suction or vacuum can be applied to a tunneling wound to promote wound drainage and wound healing. A challenge in treating tunneling wounds with suction is that it can be difficult to place a dressing into a deep tunneling wound so that the dressing can effectively facilitate the removal of wound exudates. Another challenge in treating tunneling wounds with suction arises because the application of vacuum causes intimate contact between tissue and dressing materials, which can cause the tunnel dressing materials to stick to or become entangled with the wound surface. Entanglement or sticking of the dressing to the wound tissue creates a risk that pieces of the dressing can be broken off and left in the wound when the dressing is removed, and because the tunneling wound is deep, these pieces are not detectable by the clinician removing the dressing. Entanglement or sticking of the dressing to the wound tissue can also cause considerable pain to a patient when the dressing is removed.
Accordingly, it would be desirable to provide a tunnel dressing that can be placed in a tunneling wound so that vacuum can effectively reach the deepest parts of the wound to remove wound exudates and to put beneficial strain on the wound tissue. The dressing should be easy to insert into a tunneling wound. Additionally, the dressing should be easily removable from the tunneling wound without excessive entanglement or sticking to the wound tissue, and strong enough so that it can be removed from the wound in one piece without breaking and leaving small or large pieces in the wound. A tunnel dressing that allows vacuum to effectively reach the deepest parts of the wound also enables fluids to be removed from the deepest parts of the wound, which helps to avoid entrapment of fluid that can lead to an abscess.
Various dressings for use in tunneling wounds during suction therapy have been devised in the prior art. Some dressings employ generally solid rubber (e.g., silicone) or plastic devices having distinct holes or channels formed or cut into them for the purpose of transporting fluids. Other dressings employ a tube-like device having holes extending through the tube walls. There are several disadvantages to these types of devices. Because these devices are constructed from an impermeable material having discrete holes, vacuum cannot be applied uniformly and is thus concentrated on a relatively small portion of the wound surface. Further, the material from which these devices are formed is relatively inflexible, making it difficult and uncomfortable for the patient when the devices are inserted into a wound. Still further, the presence of discrete holes provides space into which large protrusions of tissue can grow, which can cause considerable pain when the devices are removed from a wound.
Still other vacuum dressings employ foam having an open cell structure for transporting fluids. When used for tunneling wounds, such dressings are supplied as a rectangular piece of foam that must be cut by a clinician to match the estimated size of the tunneling wound. A disadvantage of using foam is that foam lacks any significant tensile strength and thus is prone to break when being extracted from the wound, leaving pieces behind within the tunneling wound cavity. Moreover, it is not possible to readily discern when a piece of foam has broken off and remains lodged in the wound, because a torn or cut edge of the foam appears the same as a broken edge. The problem with foam is so significant and well known that after a clinician has cut a piece of foam to size, he or she is trained to tug on the foam piece to try to ascertain if it is strong enough prior to insertion. A further disadvantage of foam is that the foam lacks the stiffness required to push it into many tunneling wounds, so that a clinician often must use a long Q-tip or other ad hoc device to help push the foam dressing into the wound.
Yet other vacuum dressings utilize a tube interconnecting between a suction source at one end and a pad disposed at the opposite end, the tube otherwise having no holes or apertures to communicate vacuum to the wound. In use, the device is placed with the pad deep inside the wound and the tube partly disposed within the wound and extending out from the wound. Any unfilled space surrounding the tube within the wound may be filled with gauze. Numerous disadvantages result from this type of arrangement. Often a tunneling wound is too narrow to allow the pad (with the connected tube) to be placed deep within the wound and to subsequently completely surround the tube with gauze. Further, the device effectively applies vacuum forces only to the wound surface that is in contact with the pad or is in contact with whatever gauze can be packed in around the tube. Thus, the applied suction will generally be able to evacuate exudates from a wound but will be unable to apply suction forces to tissue that is in contact with only the tube. Still further, when the pad is made from foam, all of the problems discussed above with regard to foam dressings may result. In addition, the pad can become detached from the end of the tube and left in the wound when the device is withdrawn. Also, there is no mechanism for introducing the device into a deep tunnel wound other than by pushing on the flexible tube.